Why can’t it be cleaned what errors or warnings are given (file in use, etc.) ?
Is avast able to detect it ?
If so it should be able to deal with it, if you have XP, vista32bit or Win2k, you could enable a boot time scan. Right click the avast icon, select Start avast! Antivirus, Menu, ‘Schedule boot-time scan…’ Or see http://www.digitalred.com/avast-boot-time.php.
In windows explorer, Tools, Folder Options, View, Hidden Files and folders ensure that you enable show hidden files and folders and disable the do not show hidden or system files, see image and ensure your settings are the same for the ones to the right of the Red line.
Yes , Avast can direct it when it is a normal file or a hidden file , but if it is a system & hidden file , I can see it in explorer, but avast can’t find that.
And then , I copy this file into a rar file , scanning by avast, just OK …
Change your system settings to show hidden files and folders and also display hidden system files, see image and replicate the settings opposite the Red line. Windows Explorer, Tools, Folder Options, scroll down to the Hidden Files and Folders section.